JP3556871B2 - Alternator control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an alternator control device, and more particularly to an alternator control device suitable for use in, for example, a vehicle or the like that controls the voltage generated by an alternator by an ON / OFF duty ratio of an applied voltage to an exciting coil.
[0002]
[Prior art]
Conventionally, an alternator control device to be achieved by digital control by a microcomputer with respect to feedback control of a voltage generated by an alternator to a target voltage is described in Japanese Patent Laid-Open No. 05-176477.
In this type of conventional alternator control device, when feedback control is performed by causing the generated voltage of the alternator to follow the target voltage, the target excitation current corresponding to the target generated current of the alternator is calculated by an equation based on the power generation characteristics of the alternator. The predicted excitation current that will actually flow through the excitation coil is calculated using an equation based on the electromagnetic specifications of the alternator.
[0003]
Then, the target excitation current based on the deviation between the value of the target excitation current obtained by this calculation and the value of the predicted excitation current is converted into the power generation characteristics and electromagnetic specifications of the alternator (for example, the number of turns of the excitation winding constituting the alternator). Based on this, the primary advance correction is performed, and the control excitation current is calculated.
Next, the ON / OFF duty ratio with respect to the control excitation current determined by the calculation is selected and read from a memory having a table set in advance based on the electromagnetic specifications of the alternator. The applied voltage to the exciting coil is controlled based on the ON / OFF duty ratio read from the memory.
[0004]
[Problems to be solved by the invention]
By the way, in the conventional alternator control apparatus configured as described above, when the alternator's power generation characteristics and electromagnetic specifications are changed, or when diverted to an alternator having other electromagnetic specifications and power generation characteristics, the control apparatus It is necessary to change the table of the ON-OFF duty ratio with respect to the control excitation current and the coefficient of the calculation equation of the excitation current for each electromagnetic specification and power generation characteristic of the alternator, and to re-match, the correction work is complicated and many There was a problem that it took a long time.
[0005]
The present invention has been made to solve the above-described problems, and the alternator is also used when the alternator's power generation characteristics and electromagnetic specifications are changed, or when the alternator has other electromagnetic specifications and power generation characteristics. An object of the present invention is to provide a control device.
[0006]
[Means for Solving the Problems]
An alternator control device according to claim 1 is an alternator control device that controls a voltage generated by an alternator based on an ON / OFF duty ratio of a voltage applied to an excitation coil of the alternator. An arithmetic means for comparing the deviation with a predetermined value according to the voltage deviation, a correction means for converging the generated voltage of the alternator to the target voltage according to the comparison result of the arithmetic means, and according to a convergence result of the correction means And a search means for searching the ON / OFF duty ratio of the applied voltage to the alternator between a predetermined minimum duty ratio and a predetermined maximum duty ratio based on a binary search method.
[0007]
According to a second aspect of the present invention, there is provided the control device for an alternator according to the first aspect, wherein the search means is configured such that the generated voltage of the alternator is compared with a target voltage during the search for the ON / OFF duty ratio of the applied voltage. When a certain voltage deviation occurs, the search depth is reset and the search is restarted from the beginning.
[0008]
According to a third aspect of the present invention, there is provided a control device for an alternator according to the first or second aspect of the present invention, wherein the search means is provided with a predetermined search depth limit, and the ON / OFF duty ratio determined by the search depth limit is divided into two. The end of the search for the ON / OFF duty ratio by the search method is determined.
[0009]
According to a fourth aspect of the present invention, there is provided the control device for an alternator according to the third aspect of the present invention, wherein the correction means is configured to increase and decrease by a predetermined increment when the binary search reaches a predetermined search depth limit by the search means. Thus, the ON / OFF duty ratio of the applied voltage is finely adjusted.
[0010]
According to a fifth aspect of the present invention, there is provided the alternator control device according to the fourth aspect of the invention, wherein the correcting means provides a predetermined time limit to a decrease amount of the ON / OFF duty ratio that decreases with a predetermined decrement. Is temporally suppressed.
[0011]
According to a sixth aspect of the present invention, there is provided the alternator control device according to any one of the first to fifth aspects, wherein a predetermined increment is added to the ON / OFF duty ratio of the applied voltage in accordance with a comparison result of the arithmetic means. An adding means is provided.
[0012]
According to a seventh aspect of the present invention, there is provided the alternator control device according to the sixth aspect of the present invention, wherein the adding means provides a predetermined time limit to the increase amount of the ON / OFF duty ratio of the applied voltage that increases in a predetermined increment. And a suppression means for suppressing the increase in time.
[0013]
According to an eighth aspect of the present invention, in the control device for an alternator according to the seventh aspect of the invention, the suppression means cancels or reduces the time suppression of the increase amount within a predetermined increase amount range.
[0014]
An alternator control device according to a ninth aspect of the present invention is the control device according to the seventh or eighth aspect, wherein the suppression means changes the amount of increase per time depending on the drive rotational speed of the alternator.
[0015]
An alternator control device according to a tenth aspect of the present invention is the alternator control device according to any one of the first to ninth aspects, wherein a temperature detection element is provided in the control device, and based on the internal temperature of the control device detected by the temperature detection element. The battery temperature is estimated.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings, taking as an example a case where the present invention is applied to a control device for an alternator for a vehicle.
Embodiment 1 FIG.
1 is a block diagram showing an alternator control apparatus according to Embodiment 1 of the present invention.
In the figure, the control device has a microcomputer 1 and a plurality of terminals T1 to T6 connected to an external unit (not shown). The microcomputer 1 is dedicated to alternator power generation control, May be included inside. Further, the configuration in FIG. 1 is based on the assumption that the alternator control device is installed in the alternator or adjacent to the outside of the alternator.
[0017]
When the alternator control function is included in the microcomputer of the engine ECU, the engine ECU itself recognizes the engine speed, so there is no need to separately acquire the drive speed of the alternator, but the microcomputer is dedicated to alternator power generation control. If it is installed in another place, unless an external unit such as an engine ECU is connected to an engine rotation signal line, if an alternator drive rotation speed or engine rotation speed is required for its control, It is necessary to convert the rotation by taking in the voltage waveform of the one-phase output of the alternator stator.
[0018]
A predetermined power supply voltage is supplied to the microcomputer 1 from a power supply 2, and the power supply 2 is connected to a terminal T1 via an interface (I / F) 3, and this terminal T1 is connected to B ( Connected to the (power) terminal. A battery (not shown) is also connected to the terminal T1.
[0019]
A wakeup trigger 4 is connected to the power source 2. The microcomputer 1 is not turned on when an ignition key (not shown) of the vehicle is OFF. A trigger for starting the microcomputer 1 is detected by a wakeup trigger 4. The wakeup trigger 4 monitors the voltage signal VS1 at the terminal T5 connected to the external unit or the voltage signal VS2 at the terminal T6 connected to an alarm lamp (not shown), and the voltage signal VS1 or VS2 is LOW. The power source 2 of the microcomputer 1 is turned on when shifting from HIGH to HIGH.
[0020]
After startup, the microcomputer 1 takes in the generated voltage of the alternator from the terminal T1 to the A / D conversion port via the interface (I / F) 5 in order to achieve power generation control of the alternator. This A / D conversion port is a port for recognizing the voltage generated by the alternator. The microcomputer 1 processes the generated voltage of the alternator fetched from the A / D conversion port in a function block of power generation control shown in FIG. 2 described later.
[0021]
The PO port or PWM port of the microcomputer 1 is connected to the control electrode of the switch 7 via an interface (I / F) 6. As the switch 7, a semiconductor switching element driven by current or voltage, for example, a MOSFET or a bipolar transistor is used. One main electrode of the switch 7 is connected to the terminal T2 and connected to the terminal T1 via the surge absorbing diode 8, and the other main electrode is grounded via the resistor 9 and the interface (I / F) is connected to the A / D conversion port of the microcomputer 1 via 10.
[0022]
Terminal T2 is connected to the negative side of the exciting coil of the alternator. ON / OFF of the applied voltage to the exciting coil of the alternator is performed by driving the switch 7 from the PO port or PWM port of the microcomputer 1 via the interface 6. The microcomputer 1 outputs a so-called ON / OFF duty pulse from the PO port or the PWM port, converts this into a current or a voltage at the interface 6 and drives the switch 7. The resistor 9 is provided for estimating the excitation current on the microcomputer 1 side based on the voltage drop, for example.
[0023]
The PO port or A / D conversion port of the microcomputer 1 is connected to a terminal T3 via an interface (I / F) 11, and this terminal T3 is connected to the one-phase output side of the alternator stator. The terminal T4 is grounded.
The microcomputer 1 takes in the one-phase voltage of the stator that is generating the alternator to the PO port via the interface 11, and the voltage waveform approximates a rectangular wave. By measuring the frequency of the voltage, the alternator drive speed and If necessary, the engine speed can be obtained by the circumferential ratio of the alternator pulley and the engine crank pulley, that is, the pulley ratio.
[0024]
The port of the microcomputer 1 connected to the interface 11 may be an A / D conversion port instead of the PO port depending on the control contents. For example, an A / D conversion port is used to recognize the start of power generation or power generation failure of the alternator by obtaining the peak voltage of the voltage waveform from the terminal T3.
[0025]
The interface 11 may be provided with a comparison circuit capable of discriminating the voltage level. In this case, the microcomputer 1 does not need to recognize the voltage. Therefore, the port is also a normal port for discriminating only HIGH / LOW of the pulse. That is, a PO port may be used.
[0026]
A terminal T5 connected to the external unit is connected to the SCI port of the microcomputer 1 through an interface (I / F) 12. The PO port of the microcomputer 1 is connected to the control electrode of the switch 14 via the interface (I / F) 13. Similarly to the switch 7, the switch 14 is a semiconductor switch element driven by current or voltage, for example, a MOSFET or a bipolar transistor. One main electrode of the switch 14 is connected to a terminal T6 to which an alarm lamp (not shown) or the like is connected, and the other main electrode is grounded.
[0027]
The switch 14 is driven to turn on an alarm lamp or the like when the microcomputer 1 determines that it is necessary. The switch 14 is driven, for example, when the alternator determines that the microcomputer 1 has failed to generate power, and alerts the outside by turning on an alarm lamp or the like.
[0028]
Further, the temperature detection element 15 is connected to the microcomputer 1 via an interface (I / F) 16. The temperature detection element 15 is, for example, a thermistor or a diode that detects the temperature inside the control device, and the microcomputer 1 estimates the battery temperature based on the temperature detected by the temperature detection element 15.
[0029]
FIG. 2 is a block diagram functionally showing alternator power generation control by the microcomputer 1.
The basic parameters necessary for this control method are the generator voltage and the target voltage of the alternator, and the voltage deviation ΔV is feedback-controlled. The target voltage setting unit 21 detects by the temperature detection element 15 as described above. The apparatus temperature may be reflected in the target voltage, or the target voltage may be changed by an instruction from an external unit such as an engine ECU connected to the terminal T5.
[0030]
The adder 22 calculates the voltage deviation ΔV between the target voltage from the target voltage setting unit 21 and the alternator generation voltage obtained at the A / D conversion port via the interface 5, and supplies it to the calculation unit 23. In the calculation unit 23, the voltage deviation ΔV substantially obtained from the basic parameters is classified into CASE1 to CASE4 under the conditions shown in FIG. The target voltage setting unit 21, the adder 22, and the calculation unit 23 constitute a calculation unit.
[0031]
In the following description, the predetermined values TH1, TH2, and TH3 substantially represent reference values for voltage deviation, and the magnitude relationship is as follows.
TH1 ≦ TH2 <TH3
[0032]
CASE1: When | ΔV | is less than a predetermined value TH1
The absolute value | ΔV | of the voltage deviation ΔV being less than the predetermined value TH1 indicates that the voltage deviation is within a range allowed for voltage control. When | ΔV | is within this voltage deviation range, the ON / OFF duty ratio of the applied voltage to be output is determined to be the already determined ON / OFF duty ratio and is not changed. Therefore, in this case, the calculation unit 23 supplies the output directly to the drive unit 33, whereby the switch 7 (FIG. 1) is driven.
[0033]
Here, the already determined ON / OFF duty ratio is the duty ratio of the applied voltage output last time, and since there is no concept of the previous output in the first first time, any duty ratio is determined in advance. I will leave. If it is determined based on the binary search flow shown in FIG. 3, the initial ON / OFF duty ratio is 50%.
[0034]
In general, the first ON / OFF duty ratio of the alternator is an ON duty ratio for achieving a state called initial excitation. For example, if this is 20%, the initial ON duty ratio is 20%. Should be. However, when the alternator is in the initial excitation state, the generated voltage does not normally satisfy the target voltage, and if the search for the ON / OFF duty ratio described later is started, the ON duty ratio should try to increase. Therefore, a phenomenon occurs that the initial excitation is lost during the initial excitation.
[0035]
In order to avoid this, it is necessary to determine the ON / OFF duty ratio during the initial excitation of the alternator with some intention and not to search. Some intention here is to fix at 20%, or to decrease without increasing from 20%, or engine startability improvement control called start response ( When starting the engine, it is necessary to take into consideration that the exciting current is not passed to avoid the generator torque of the alternator, or that the control is limited to a predetermined upper limit value.
[0036]
CASE2: When | ΔV | is not less than a predetermined value TH1 and not more than a predetermined value TH2.
When | ΔV | is equal to or greater than the predetermined value TH1, the ON / OFF duty ratio of the output pulse does not satisfy the excitation current required by the alternator, and it is necessary to change the ON / OFF duty ratio. Here, if the ON / OFF duty ratio is changed in the first convergence correcting unit 24 based on the binary search flow shown in FIG. 3, the excitation current converges to the ON / OFF duty ratio to be satisfied.
[0037]
Although this alone can control the voltage generated by the alternator, there is a time constant in the increase / decrease of the excitation current, and the ON / OFF duty ratio of the applied voltage that is output is not immediately reflected in the excitation current. When the speed exceeds the increase / decrease time constant of the excitation current, an ON / OFF duty ratio having an ON ratio that is larger or smaller than planned is obtained.
[0038]
Even if you try to correct too much and too little from there, it will always repeat whether it is larger or smaller, and as a result, the excitation current will not be stable and the generated voltage of the alternator will fluctuate and the ON / OFF duty The ratio is not stable. FIG. 4 shows how the duty ratio moves in this case.
[0039]
In the present embodiment, means for improving this are incorporated at the same time, and before changing the duty ratio based on the binary search flow, the ON / OFF duty ratio of 0% or 100% is set. The excitation current is rapidly corrected so that the generated voltage becomes the target voltage by continuous output. That is, 100% is continuously output when the generated voltage is negative ΔV with respect to the target voltage, and 0% is continuously output when the generated voltage is positive ΔV. The search progression unit 25 proceeds to search for the duty ratio based on the binary search flow in the state of the excitation current raised by the rapid correction.
[0040]
Although the duty ratio is searched here, if the search depth is at the limit, the duty ratio determined by the fine adjustment unit 26 is finely adjusted by a predetermined increment and decrement. Here, the search depth is the first column (50%), the second column (75%, 25%), the third column (87%... 12%), the fourth column from the leftmost end in FIG. The column (93%... 7%) and the fifth column (95%... 5%) refer to the progress toward the right end. In this case, the fifth column on the right end represents the search depth limit. FIG. 5 shows the behavior of the duty ratio achieved by the control described above and the behavior of the voltage generated by the alternator.
[0041]
CASE3: When | ΔV | exceeds a predetermined value TH2
(However, if ΔV is negative, it is less than the predetermined value TH3)
When | ΔV | exceeds the predetermined value TH2, it is determined that there is a sudden increase or decrease in the vehicle load and the excitation current is very large or very small. Even in this case, the act of searching for the duty ratio based on the binary search flow after the excitation current is rapidly corrected in the second convergence correction unit 27 is the same as in CASE2.
[0042]
However, the necessary excitation current of the alternator has completely changed, that is, when the ON / OFF duty ratio is in the search process based on the binary search flow, the convergence destination is not correct before convergence. End up. Even if this is left unattended, it will eventually converge to the ON / OFF duty ratio that satisfies the required excitation current, but here the first search depth reset unit 28 resets the search depth of the binary search flow and searches for the duty ratio. By redoing, it becomes possible to improve the response of the exciting current change to a sudden increase or decrease in vehicle load.
[0043]
The first convergence correction unit 24, the fine adjustment unit 26, and the second convergence correction unit 27 constitute a correction unit, and the search progression unit 25, the first search depth reset unit 28, and the search execution unit 32 constitute a search unit. .
[0044]
CASE 4: When ΔV is negative and exceeds a predetermined value TH3
In the first addition unit 29, a predetermined increment is added to the ON / OFF duty ratio of the applied voltage, with the kick-on amount and dead zone as initial increments without time suppression. As a result, it is possible to improve the voltage stability in a situation where an intermittent vehicle load (hazard lamp or the like) called a kick-on amount or dead zone is applied.
[0045]
Here, when ΔV is negative and exceeds the predetermined value TH3, that is, when the generated voltage exceeds the predetermined value and is smaller than the predetermined value, it is determined that the vehicle load is suddenly applied. The difference from CASE 3 is that the subsequent processing is limited only in a significant increase direction even in the case of a sudden increase or decrease in vehicle load. In this situation, immediately increasing the excitation current as in the process in CASE 3 will suddenly increase the power generation drive torque of the alternator, which will give a sudden torque shock to the engine.
[0046]
In order to avoid this, in this case, an increase in the ON / OFF duty ratio is temporally suppressed. That is, from the previous ON / OFF duty ratio on the binary search flow, the increment limited per time is added by the second adder 30 until the target voltage is satisfied. The first addition unit 29 and the second addition unit 30 constitute addition means.
[0047]
Similar to the first search depth reset unit 28, the second search depth reset unit 31 temporarily resets the search depth of the binary search flow and redoes the search of the duty ratio, so that the sudden increase or decrease of the vehicle load can be prevented. It becomes possible to improve the response of the excitation current change.
The search execution unit 32 performs search execution based on the outputs of the search progression unit 25, the first search depth reset unit 28, and the first search depth reset unit 31, and drives the drive unit 33.
[0048]
Next, the operation will be described with reference to FIG.
First, the generated voltage of the alternator is read (step S1), and the voltage deviation ΔV between the generated voltage and the target voltage is calculated (step S2). Then, it is determined whether or not the absolute value | ΔV | of the voltage deviation ΔV is smaller than the predetermined value TH1 (step S3), and if it is smaller, the voltage deviation is within the range allowed for voltage control, so the ON / OFF duty ratio is changed. Otherwise, the predetermined ON / OFF duty ratio is output (step S4). (CASE1)
[0049]
On the other hand, if | ΔV | is greater than the predetermined value TH1, it is determined whether or not | ΔV | is equal to or less than the predetermined value TH2 (step S5). In this case, the ON / OFF duty ratio of the output applied voltage does not satisfy the excitation current required by the alternator, and it is necessary to change the ON / OFF duty ratio.
[0050]
Here, if the ON / OFF duty ratio is changed based on the binary search flow shown in FIG. 3, it will eventually converge to the ON / OFF duty ratio that should satisfy the excitation current. Since there is a time constant, the ON / OFF duty ratio of the applied voltage that is output is not immediately reflected in the excitation current, so if the speed of duty change exceeds the increase / decrease time constant of the excitation current, it is larger or less than planned It becomes ON / OFF duty ratio with such ON ratio.
Therefore, before changing the duty ratio based on the 2-minute search flow, the excitation current is rapidly changed so that the generated voltage becomes the target voltage by continuously outputting the ON / OFF duty ratio of 0% or 100%. Correct it.
[0051]
That is, when the generated voltage is lower than the target voltage, ON duty is output, and when it is higher, OFF duty is output (step S6), the generated voltage of the alternator is read (step S7), and it is determined whether the generated voltage is equal to the target voltage. (Step S8), if not equal, return to Step S6 and repeat the above operation, and if equal, proceed to Step S9.
[0052]
Then, in step S9, it is determined whether or not the binary search is the limit depth (search depth limit). If the limit search is not the limit depth, the ON / OFF duty ratio binary search progresses, that is, it is lifted by rapid correction. The search for the duty ratio is performed based on the binary search flow in the state of the excited current (step S10).
Subsequently, an ON / OFF duty ratio search based on the binary search method is performed (step S11), and then the process returns to step S1 to repeat the above operation.
[0053]
On the other hand, if the binary search is the limit depth in step S9, the ON / OFF duty ratio is increased or decreased by a predetermined amount. In other words, when the duty ratio is searched but the search depth is at the limit, the determined duty ratio is finely adjusted by a predetermined increment and decrement. (CASE2)
[0054]
If | ΔV | is larger than the predetermined value TH2 in step S5, it is determined whether or not the negative voltage deviation −ΔV is larger than the predetermined value TH3 (step S13). If it is smaller, | ΔV | If TH2 is exceeded, it is determined that there is a sudden increase or decrease in vehicle load and the excitation current is very high or very low. Even in this case, the act of searching for the duty ratio based on the binary search flow after rapidly correcting the excitation current is the same as in the case of CASE2.
[0055]
Therefore, before changing the duty ratio based on the 2-minute search flow, the excitation current is rapidly changed so that the generated voltage becomes the target voltage by continuously outputting the ON / OFF duty ratio of 0% or 100%. Correct it.
[0056]
That is, when the generated voltage is lower than the target voltage, ON duty is output, and when it is higher, OFF duty is output, and the generated voltage of the alternator is read (step S15), and it is determined whether the generated voltage is equal to the target voltage (step S16). ), If not equal, return to step S14 to repeat the above operation, and if equal, proceed to step S17.
[0057]
Here, the necessary excitation current of the alternator has completely changed, that is, when the ON / OFF duty ratio is in the search process based on the binary search flow, the convergence destination is not correct before the convergence. In step S17, the ON / OFF duty ratio binary search depth is reset, and then the ON / OFF duty ratio search is executed based on the binary search method (step S18), and then the process returns to step S1. The above operation is repeated. (CASE3)
[0058]
Further, when -ΔV is larger than the predetermined value TH3 and ΔV is negative and exceeds the predetermined value TH3 in step S13, that is, when the generated voltage exceeds the predetermined value with respect to the target voltage, it is suddenly turned on. to decide. Therefore, the most recent ON / OFF duty ratio determined in the binary search is output (step S19), and a predetermined increment is added to the ON / OFF duty ratio of the applied voltage to be output (step S20). That is, in step S20, as described above, a predetermined increment is added to the ON / OFF duty ratio of the applied voltage with the kick-on amount and dead zone as initial increments without time suppression.
[0059]
Then, the generated voltage of the alternator is read (step S21), it is determined whether or not the generated voltage and the target voltage are equal (step S22), and if not, it is determined whether or not the increase in the ON / OFF duty ratio has reached a predetermined amount. If it has not been reached, the process returns to step S20 to repeat the above operation, and if it has reached, the process proceeds to step S24.
[0060]
In step S24, the time-suppressed increment is added to the ON / OFF duty ratio of the applied voltage to be output and output. In other words, if the excitation current is increased immediately as in the case 3 as described above, the generator driving torque of the alternator is suddenly increased, which causes a sudden torque shock to the engine. In order to avoid this, an increase in the ON / OFF duty ratio is temporally suppressed.
[0061]
Next, the generated voltage of the alternator is read (step S25), it is determined whether the generated voltage is equal to the target voltage (step S26), and if not equal, the process returns to step S24 and the above operation is repeated. That is, an increment limited per time is added from the previous ON / OFF duty ratio on the binary search flow until the target voltage is satisfied. When the voltage generated by the alternator becomes equal to the target voltage, the process proceeds to step S27.
[0062]
Here, steps S19 to S26 are cases in which the increase amount of the ON / OFF duty ratio of the applied voltage that increases in a predetermined increment is temporally suppressed.
An example will be described in detail using appropriate numerical values.
Now, the ON / OFF duty ratio of the target applied voltage is 50%, the ON / OFF duty ratio of the applied voltage output in step S19 is 20%, the predetermined increment is 5%, the predetermined amount in step S23 is 30%, Assuming that the time-suppressed increment in step S24 is 1%, in step S20, a predetermined increment of 5% is added to the ON / OFF duty ratio of 20% from step S19, and this is added to the predetermined amount 30 in step S23. Repeat between steps S20 to S23 until% is reached.
[0063]
When the predetermined amount of 30% is achieved, that is, when the repetition is performed six times between steps S20 to S23, the target ON / OFF duty ratio of the applied voltage becomes 50%. Since the target voltage has not been reached, the process proceeds to step S24.
[0064]
In step S24, the time-suppressed increment of 1% is added to the ON / OFF duty ratio of the applied voltage to be output. In other words, the increase amount of the ON / OFF duty ratio is substantially suppressed temporally, and the alternator The same operation is repeated until the generated voltage reaches the target voltage.
[0065]
Then, the binary search depth of the ON / OFF duty ratio is reset in step S27, and then the search execution of the ON / OFF duty ratio based on the binary search method is performed (step S28), and then the process returns to step S1 and described above. Repeat the operation. (CASE4)
[0066]
Thus, in the present embodiment, the ON / OFF duty ratio is set between the predetermined minimum duty ratio and the predetermined maximum duty ratio based on the binary search method so that the generated voltage of the alternator converges to the target voltage. Since the search is performed, when the alternator is controlled and the generated voltage is feedback-controlled to the target voltage, the control device does not need parameters or equations based on the power generation characteristics or electromagnetic specifications of the alternator.
[0067]
That is, it is not necessary to change the parameters or equations of the control device due to changes in the power generation characteristics or electromagnetic specifications of the alternator. Therefore, feedback control can be achieved without calculating the excitation current with an equation based on the power generation characteristics and electromagnetic specifications of the alternator and converting it into an ON / OFF duty ratio as in the prior art.
[0068]
In addition, it is possible to quickly respond to the electromagnetic specifications of the alternator over a wide range without changing the specifications of the control device. In addition, since the ON / OFF duty ratio of the applied voltage to the exciting coil is substantially determined at a fixed frequency, when this is recognized by an electric circuit or a microcomputer, its configuration becomes easy. A configuration for estimating the power generation torque is conceivable.
[0069]
In addition, during the search for the ON / OFF duty ratio, when the voltage generated by the alternator has a predetermined voltage deviation with respect to the target voltage, the search depth is reset and the search is restarted from the beginning. Even in such a case, the voltage generated by the alternator can be quickly corrected.
[0070]
In addition, a predetermined search depth limit is provided, and the ON / OFF duty ratio determined by the search depth limit is used to determine the end of the search for the ON / OFF duty ratio by the binary search method, so that the power generation torque of the alternator is estimated. / OFF duty ratio can be determined.
Further, when the predetermined search depth limit is reached, the ON / OFF duty ratio is finely adjusted by a predetermined increment and decrement, so that the stability of the generated voltage of the alternator can be improved.
[0071]
In addition, since a predetermined time limit is provided for the increase amount of the ON / OFF duty ratio that increases in a predetermined increment and the increase amount is temporally suppressed, it is possible to prevent an abrupt increase in the power generation torque of the alternator.
In order to prevent this sudden increase in the generator torque, that is, to reduce the responsiveness of the alternator's power generation to the target power, the intermittent load such as a hazard lamp or blinker when the vehicle is stopped. On the other hand, the responsiveness becomes poor, and the brightness of the lamps in the room lamp and the meter causes visual discomfort. In this case, the increase time is suppressed within a predetermined increase range. Is reduced or reduced, or the amount of decrease in the ON / OFF duty ratio that decreases with a predetermined decrement is set with a predetermined time limit to suppress the decrease over time. Causes can be eliminated or reduced.
[0072]
In addition, when the amount of increase is suppressed, the amount of increase per hour is changed depending on the drive rotation speed of the alternator. When the value is high, the drop in the generated voltage can be reduced.
[0073]
Also, a temperature detection element such as a thermistor element is provided inside the control device, and the battery temperature is estimated based on the internal temperature of the control device detected from this temperature detection element. Therefore, the charging voltage considering the temperature characteristics of the battery charging efficiency Thus, the battery life can be extended.
[0074]
【The invention's effect】
As described above, according to the first aspect of the present invention, the arithmetic means for comparing the deviation with a predetermined value according to the deviation between the generated voltage of the alternator and the target voltage, and the alternator according to the comparison result of the arithmetic means. Correction means for converging the generated voltage to the target voltage, and an ON / OFF duty ratio of the applied voltage to the alternator between the predetermined minimum duty ratio and the predetermined maximum duty ratio according to the convergence result of the correction means Searching means based on the partial search method is provided, so that the alternator is controlled to change the generated voltage to the target voltage without changing the parameters or equations of the control device due to changes in the power generation characteristics or electromagnetic specifications of the alternator. Feedback control is possible, and it is possible to respond quickly to the electromagnetic specifications of a wide range of alternators without changing the specifications of the control device. , Moreover, since the ON / OFF duty ratio of applied voltage to the exciting coil is determined at a substantially fixed frequency, in the case of recognizing this in electric circuits, a microcomputer, there is an effect that the configuration becomes easier.
[0075]
According to a second aspect of the present invention, the search means searches when a voltage deviation occurs between the generated voltage of the alternator and the target voltage during the search of the ON / OFF duty ratio of the applied voltage. Since the depth is reset and the search is restarted from the beginning, there is an effect that the generated voltage of the alternator can be quickly corrected even when a sudden electric load is applied.
[0076]
According to the invention of claim 3, the search means is provided with a predetermined search depth limit, and the search for the ON / OFF duty ratio by the binary search method is completed with the ON / OFF duty ratio determined by the search depth limit. Therefore, the ON / OFF duty for estimating the power generation torque of the alternator can be determined.
[0077]
According to a fourth aspect of the present invention, when the binary search reaches a predetermined search depth limit by the search means, the correction means sets the ON / OFF duty of the applied voltage with a predetermined increment and decrement. Since the ratio is finely adjusted, the stability of the voltage generated by the alternator can be improved.
[0078]
According to a fifth aspect of the present invention, the correction means provides a predetermined time limit to the amount of decrease in the ON / OFF duty ratio that decreases with a predetermined decrement, and suppresses the decrease in time. On the other hand, when the power generation torque is suddenly increased, the responsiveness of the increase in the generated power of the alternator with respect to the target power becomes worse, and the brightness of the lamps in the room lamp and the meter may cause visual discomfort. There is an effect that it can be eliminated or reduced.
[0079]
Further, according to the invention of claim 6, since the adding means for adding a predetermined increment to the ON / OFF duty ratio of the applied voltage according to the comparison result of the calculating means is provided, it is called a kick-on amount or a dead zone. There is an effect that the voltage stability in the situation where the intermittent vehicle load is applied can be improved.
[0080]
According to a seventh aspect of the present invention, the adding means provides a predetermined time limit on the increase amount of the ON / OFF duty ratio of the applied voltage that increases in a predetermined increment, and suppresses the increase amount in terms of time. Therefore, there is an effect that an abrupt increase in the power generation torque of the alternator can be prevented.
[0081]
Further, according to the invention of claim 8, the suppression means cancels or reduces the time suppression of the increase amount within a predetermined increase amount range, so when preventing a sudden increase in the power generation torque of the alternator, On the contrary, there is an effect that the responsiveness of the increase in the generated power of the alternator with respect to the target power is deteriorated, and the brightness of the lamp in the room lamp or the meter can be eliminated or reduced visually.
[0082]
According to the invention of claim 9, since the suppression means changes the amount of increase per time depending on the drive rotation speed of the alternator, the engine rotation is reduced when the engine rotation is low in the power generation torque increase when the electric load is turned on. When the engine speed is high, the drop in the generated voltage can be reduced.
[0083]
Furthermore, according to the invention of claim 10, since the temperature detection element is provided in the control device and the battery temperature is estimated based on the internal temperature of the control device detected by the temperature detection device, the temperature characteristic of the charging efficiency of the battery With the charging voltage considering the above, there is an effect that the life of the battery can be extended.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of the present invention.
FIG. 2 is a block diagram functionally showing a main part of one embodiment of the present invention.
FIG. 3 is a diagram showing a binary search flow in one embodiment of the present invention.
FIG. 4 is a diagram for explaining an operation in an embodiment of the present invention.
FIG. 5 is a diagram for explaining an operation in an embodiment of the present invention.
FIG. 6 is a flowchart for explaining an operation in an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Microcomputer, 7 switch, 15 Temperature detection element, 21 Target voltage setting part, 22 Adder, 23 Calculation part, 24 1st convergence correction part, 25 Search progress part, 26 Fine adjustment part, 27 2nd convergence correction part, 28 1st search depth reset part, 29 1st addition part, 30 2nd addition part, 32 Search execution part.

Claims (10)

In an alternator control device that controls the generated voltage of an alternator based on an ON / OFF duty ratio of a voltage applied to an excitation coil of the alternator,
An arithmetic means for comparing the deviation with a predetermined value according to the deviation between the generated voltage of the alternator and the target voltage;
Correction means for converging the generated voltage of the alternator to a target voltage according to the comparison result of the calculation means;
Search means for searching for the ON / OFF duty ratio of the voltage applied to the alternator based on a binary search method between a predetermined minimum duty ratio and a predetermined maximum duty ratio according to a convergence result of the correction means. An alternator control device characterized by that. The search means resets the search depth and restarts the search from the beginning when a voltage deviation occurs between the generated voltage of the alternator and the target voltage during the search of the ON / OFF duty ratio of the applied voltage. The alternator control device according to claim 1. The search means is provided with a predetermined search depth limit, and the ON / OFF duty ratio determined by the binary search method is determined based on the ON / OFF duty ratio determined by the search depth limit. Or the alternator control device according to 2; The correction means finely adjusts the ON / OFF duty ratio of the applied voltage by a predetermined increment and decrement when the binary search reaches a predetermined search depth limit by the search means. Item 4. The alternator control device according to Item 3. 5. The alternator control device according to claim 4, wherein the correction means provides a predetermined time limit to a decrease amount of the ON / OFF duty ratio that decreases with a predetermined decrement, and suppresses the decrease amount temporally. . 6. The alternator control device according to claim 1, further comprising addition means for adding a predetermined increment to the ON / OFF duty ratio of the applied voltage in accordance with a comparison result of the arithmetic means. . The addition means includes suppression means for providing a predetermined time limit to an increase amount of the ON / OFF duty ratio of the applied voltage that increases in a predetermined increment and suppressing the increase amount temporally. Item 7. The alternator control device according to item 6. 8. The alternator control device according to claim 7, wherein the suppression means cancels or reduces the time suppression of the increase amount within a predetermined increase amount range. The alternator control device according to claim 7 or 8, wherein the suppression means changes an increase amount per time depending on a driving rotational speed of the alternator. 10. The alternator control device according to claim 1, wherein a temperature detection element is provided inside the control device, and the battery temperature is estimated based on the internal temperature of the control device detected by the temperature detection device. .

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